Monitoring the opening and closing of a secure container such as a safe is useful in determining whether the security of the container has been violated or compromised. The present invention relates to an assembly which detects openings and closings of a safe and provides a record of such events for comparison with authorized openings and closings. The assembly includes a fiber optic loop connected with the container. Openings and closings of the container bend the loop, attenuating a light signal transmitted therethrough. The attenuations are detected and used to monitor opening and closing events.